scholarly journals Corrosion Mechanism of L360 Pipeline Steel Coated with S8 in CO2-Cl− System at Different pH Values

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1975
Author(s):  
Fan Wang ◽  
Jinling Li ◽  
Chengtun Qu ◽  
Tao Yu ◽  
Yan Li ◽  
...  
Keyword(s):  
Pipeline Steel ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
X Ray Diffraction ◽  
Intensity Index ◽  
Corrosion Scale ◽  
Electrode Cell ◽  
Corrosion Intensity ◽  
Acidic Conditions ◽  
Wire Beam Electrode

The corrosion behavior of L360 pipeline steel coated with or without elemental sulfur (S8) in CO2–Cl− medium at different pH was studied. An autoclave was used to simulate the working conditions for forming the corrosion scale, and an electrochemical workstation with a three-electrode cell was used to analyze the electrochemical characterization of the corrosion scale. A wire beam electrode was used to determine the potential and current distribution, and scanning electron microscopy and X-ray diffraction were used to characterize the morphology and composition of the corrosion scale. The results showed that the deposition of S8 on the surface of the electrodes caused serious localized corrosion, especially under acidic conditions. The morphology and localized corrosion intensity index further proved that the deposition of S8 significantly promoted corrosion, especially pitting corrosion. Finally, a novel corrosion mechanism of L360 pipeline steel coated with S8 in a CO2-Cl− environment under acidic conditions was proposed, and we then modeled the theoretical mechanisms that explained the experimental results.

Compare the Corrosion of 3%Cr Steel With X65 Pipeline Steel in Subsea CO2 Top-of-Line Corrosion Environment

2012 ◽  
Author(s):  
Yunan Zhang ◽  
Lining Xu ◽  
Wei Chang ◽  
Minxu Lu ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Pipeline Steel ◽  
Static Condition ◽  
Localized Corrosion ◽  
Good Resistance ◽  
X Ray ◽  
Corrosion Scale ◽  
Wet Gas ◽  
High Pressure High Temperature ◽  
Corrosion Scales ◽  
Series Of Experiments

CO2 Top-of-Line Corrosion (TLC) of carbon steel pipelines is a serious problem for subsea wet gas pipelines. A series of experiments were carried out in the high-pressure high-temperature condensation autoclave, in order to simulate the corrosion environment of TLC. The purpose of this paper was to compare the corrosion resistance of 3%Cr steel with API X65 pipeline steel in CO2 TLC environment. The composition and morphology of the corrosion scale were characterized by energy dispersive X-ray spectroscopy and scanning electron microscopy analyses. The results indicate that 3%Cr pipeline steel shows relative good resistance to CO2 TLC, with slight pitting at static condition, however, X65 suffers severe mesa corrosion. The analysis of composition and morphology revealed that the amorphous corrosion scales was formed on the surface of 3%Cr steel. The localized corrosion of 3%Cr steel may be related to the uneven filling of Cr compound under static condition.

A New Corrosion Mechanism for X100 Pipeline Steel Under Oil-Covered Chloride Droplets

CORROSION ◽  
10.5006/2804 ◽  
2018 ◽  
Vol 74 (9) ◽  
pp. 947-957 ◽  
Author(s):  
Hongxing Liang ◽  
Jing Liu ◽  
Rebecca Filardo Schaller ◽  
Edouard Asselin
Keyword(s):  
Pipeline Steel ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
General Corrosion ◽  
Paraffin Oil ◽  
Initial Stage ◽  
X100 Pipeline Steel ◽  
Corrosion Pits ◽  
Stage 1 ◽  
Two Stages

A 1.7 mM NaCl droplet on X100 pipeline steel covered by paraffin oil is used to simulate the corrosive environment encountered in heavy oil or bitumen pipelines. The development of corrosion under the droplet was monitored and explored in two stages. In the initial stage (1 h), the distribution of corrosion pits was heterogeneous with one area under the droplet presenting a higher pit density. As the corrosion proceeded (24 h), the localized corrosion in the area under the droplet with the higher pit density switched to general corrosion, while the other region of the droplet continued to pit. The mechanisms driving this new distinctive corrosion form developed beneath an underoil droplet are explained.

scholarly journals Effect of CO2 Partial Pressure on the Corrosion Behavior of J55 Carbon Steel in 30% Crude Oil/Brine Mixture

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1765 ◽  
Author(s):  
Haitao Bai ◽  
Yongqing Wang ◽  
Yun Ma ◽  
Qingbo Zhang ◽  
Ningsheng Zhang
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Crude Oil ◽  
Partial Pressure ◽  
Initial Period ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
Corrosion Properties ◽  
Co2 Partial Pressure ◽  
Corrosion Scale

The influence of CO2 partial pressure on the corrosion properties, including corrosion rate, morphology, chemical composition, and corrosion depth, of J55 carbon steel in 30% crude oil/brine at 65 °C was investigated. A corrosion mechanism was then proposed based on the understanding of the formation of localized corrosion. Results showed that localized corrosion occurred in 30% crude oil/brine with CO2. The corrosion rate sharply increased as the CO2 partial pressure (P co 2 ) was increased from 0 to 1.5 MPa, decreased from P co 2 = 1.5 MPa to P co 2 = 5.0 MPa, increased again at P co 2 = 5.0 MPa, and then reached a constant value after P co 2 = 9.0 MPa. The system pH initially decreased, rapidly increased, and then stabilized as CO2 partial pressure was increased. In the initial period, the surface of J55 carbon steel in the CO2/30% crude oil/brine mixtures showed intense corrosion. In conclusion, CO2 partial pressure affects the protection performance of FeCO3 by changing the formation of corrosion scale and further affecting the corrosion rate.

Experimental study on under-deposit corrosion and its inhibition using electrochemical methods and electronic coupon technique

2017 ◽  
Vol 64 (2) ◽  
pp. 148-161 ◽  
Author(s):  
Yunze Xu ◽  
Yi Huang ◽  
Limin He ◽  
Fei Yang ◽  
Xiaona Wang
Keyword(s):  
Pipeline Steel ◽  
Electrochemical Methods ◽  
Silica Sand ◽  
Localized Corrosion ◽  
Galvanic Current ◽  
Content Type ◽  
Action Effect ◽  
X65 Steel ◽  
Bare Steel ◽  
Wire Beam Electrode

Purpose In this study the aim was to investigate under-deposit corrosion (UDC) behavior and the action effects of amino trimethylene phosphonic acid (ATMP) in the oxygen-contained solution. Design/methodology/approach Electrochemical methods and wire beam electrode techniques were used for the study of ATMP action effect for X65 steel under silica sand and CaCO3 particle deposit. Electronic coupon technique was used for the study of galvanic effect caused by the deposits and the action effect of ATMP. Findings ATMP would cause localized corrosion for the silica sand-covered steel. However, it could inhibit the localized corrosion of the steel beneath CaCO3 particle deposit. Galvanic effect test showed that the galvanic effect caused by the deposits was an important factor for the acceleration of UDC. ATMP had an obvious promotion effect for the galvanic current between bare coupon and silica sand covered coupon and different degrees of localized corrosion were observed beneath both deposits. Originality/value The authors believe that the paper may be of particular interest to the readers of the journal as the measurement methods for the UDC of X65 pipeline steel. The experiment they did in the laboratory found that the inhibitor ATMP has a good inhibition effect for bare steel, but it would accelerate the UDC. Different kinds of deposits would have different influences for the UDC behavior with inhibitor added.

Water soluble biguanide salts and their 1,3,5-triazine derivatives as inhibitors of acetylcholinesterase and α-glucosidase

2020 ◽  
Vol 235 (10) ◽  
pp. 465-475
Author(s):  
Ozge Gungor ◽  
Seda Nur Kertmen Kurtar ◽  
Muhammet Kose
Keyword(s):  
Spectroscopic Method ◽  
Substitute Aniline ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Nucleophilic Reaction ◽  
X Ray ◽  
Triazine Derivatives ◽  
Acidic Conditions ◽  
Approved Drugs ◽  
Solid State Structures

AbstractSeven biguanide derivatives were prepared by the nucleophilic reaction between dicyandiamide and p-substitute aniline derivatives or memantine or adamantine under acidic conditions. The cyclization of the biguanide compounds were also conducted via acetone to give 1,3,5-triazine derivatives. The structures of the synthesized compounds were characterized by analytical methods. The solid state structures of [HL5]Cl, [H2L7]Cl2, [HL1a]Cl and [HL5a]Cl were investigated by X-ray diffraction study. The acetylcholinesterase and α-glucosidase inhibitor properties of the compounds were then evaluated by the spectroscopic method. The compounds were found to show considerable acetylcholinesterase and α-glucosidase inhibitory activities compared to the approved drugs. The cyclization of biguanide derivatives with acetone did not affect inhibition of acetylcholinesterase, yet increased the α-glucosidase inhibition.

Corrosion Resistance of Dissimilar GTA Welds of Pipeline Steel and Super Duplex Stainless Steels in Synthetic Brine

CORROSION ◽  
10.5006/3746 ◽  
2021 ◽  
Author(s):  
Víctor Vargas ◽  
Apolinar Albiter-Hernandez ◽  
Marco Dominguez Aguilar ◽  
Gerardo Altamirano-Guerrero ◽  
Cuahtemoc Maldonado
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Pipeline Steel ◽  
Localized Corrosion ◽  
Nickel Wire ◽  
Super Duplex Stainless Steel ◽  
Gas Tungsten Arc ◽  
Dissimilar Welds ◽  
Super Duplex Stainless Steels

The effect of weld passes and single V grove designs, on the corrosion resistance of dissimilar welds of a low alloy steel and a super-duplex stainless steel, was studied in synthetic brine. Welds were manufactured in argon by gas tungsten arc (GTA) technique and joined by a high nickel wire of super-duplex stainless steel. Samples of weld regions were characterized by composition scans, electrochemical measurements, micro-hardness and scanning electron microscopy. In X52/ER2594, a transition region (TR) of grain boundaries type II and a band of martensite were formed. The base metal of X52 underwent the highest corrosion rate and localized corrosion occurred in the heat affected zone. Interface ER2594/25Cr7Ni and 25Cr7Ni showed the presence of pitting near intermetallics.

scholarly journals Highly Porous Carbon Materials Filled with Nickel Hydroxide Nanoparticles; Synthesis, Study, Application in Electrochemistry

2015 ◽  
Vol 17 (3) ◽  
pp. 187 ◽  
Author(s):  
Yu.A. Zakharov ◽  
A.N. Voropay ◽  
N.M. Fedorova ◽  
V.M. Pugachev ◽  
A.V. Puzynin ◽  
...  
Keyword(s):  
Porous Carbon ◽  
Nickel Hydroxide ◽  
Nitrogen Adsorption ◽  
Porous Carbon Material ◽  
X Ray Diffraction ◽  
Scanning Rate ◽  
Electrode Cell ◽  
Adsorption Desorption ◽  
Electrode Characteristics ◽  
Study Application

<p>Nickel hydroxide was deposited on the surface of the porous carbon to obtain a cathode material for supercapacitors. This work is the first part of the study of Ni(OH)<sub>2</sub>/С composite, which considers the conditions of its synthesis using two types of porous carbon matrices with a highly developed specific surface area (1000–3000 m<sup>2</sup>/g) and two types of precursors (NiCl<sub>2</sub>*6H<sub>2</sub>O and Ni(N<sub>3</sub>)<sub>2</sub>). The morphology of the systems, in particular the shape and size characteristics of the hydroxide filler particles, was examined using the scanning electron microscopy, X-ray diffraction, and nitrogen adsorption-desorption at 77 K. The measurements of capacity of the Ni(OH)<sub>2</sub>/С-electrodes were made in 6 M KOH using an asymmetric two-electrode cell (a porous carbon material with known electrode characteristics was employed as the counter electrode). The capacity was shown to decrease by 22–56% with increasing the scanning rate from 10 to 80 mV/s. A maximum capacity of the composite was obtained at a scanning rate of 10 mV/s was 346 F/g.</p>

PERFORMANCE OF pH SENSOR ELECTRODE BASED ON ZnO NRs ON FTO-GLASS SUBSTRATE

2020 ◽  
Vol 27 (08) ◽  
pp. 1950198
Author(s):  
ABDULQADER D. FAISAL ◽  
MOHAMMAD O. DAWOOD ◽  
HASSAN H. HUSSEIN ◽  
KHALEEL I. HASSOON
Keyword(s):  
Seed Layer ◽  
Zno Nanorods ◽  
Ph Sensor ◽  
High Sensitivity ◽  
Hydrothermal Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Nanocrystals ◽  
Electrode Cell ◽  
Fto Glass

In this work, ZnO nanorods (ZnO NRs) were successfully synthesized on FTO-glass via hydrothermal technique. Two steps were followed to grow ZnO NRs. In the first step, the seed layer of ZnO nanocrystals was deposited by using a drop cast method. The second step was represented by the hydrothermal growth of ZnO NRs on a pre-coated FTO- glass with the seed layer. The hydrothermal growth was conducted at 90∘C for 2[Formula: see text]h. The resulted structure, morphology and optical properties of the produced layers were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray (EDX) and UV-visible spectrophotometer, respectively. The analysis confirmed that the ZnO NRs grown by the hydrothermal method have a hexagonal crystal structure which was grown randomly on the FTO surface. The crystallite size was recorded 50[Formula: see text]nm and a slight microstrain (0.142%) was calculated. The bandgap was found to be in the range of 3.14–3.17[Formula: see text]eV. The ZnO NRs have a high density and large aspect ratio. A pH sensor with high sensitivity was fabricated using a two-electrode cell configuration. The ZnO NRs sensor showed the sensitivity of [Formula: see text]59.03[Formula: see text]mV/pH, which is quite promising and close to the theoretical value ([Formula: see text]59.12[Formula: see text]mV/pH).

Effect of Long-Term Service Exposure on the Localized Corrosion and Stress Corrosion Cracking Susceptibility of Type 347 Stainless Steel

CORROSION ◽  
10.5006/2612 ◽  
2017 ◽  
Vol 74 (3) ◽  
pp. 350-361 ◽  
Author(s):  
K. Ravindranath ◽  
N. Tanoli ◽  
B. Al-Wakaa
Keyword(s):  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Localized Corrosion ◽  
X Ray Diffraction ◽  
Degree Of Sensitization ◽  
Corrosion Susceptibility ◽  
Service Exposure

The paper presents the results of a study conducted on the effects of long-term service exposure of Type 347 stainless steel (SS) on the microstructure and corrosion susceptibility. The material subjected to the study was in service in a petroleum refinery as heater tube at 620°C for 31 years. The microscopic and x-ray diffraction studies of the service-exposed specimen revealed the precipitation of chromium-rich carbides along the grain boundaries. The microstructural changes that occurred as a result of service exposure affected the ductility and toughness of the alloy. The sensitization of the alloy was assessed by scanning electron microscopy and double loop electrochemical potentiodynamic reactivation. The studies have indicated some degree of sensitization in the alloy. The service exposure resulted in a marginal increase in the susceptibility of Type 347 SS to pitting in environments containing NaCl and NaCl + H2S. Environments such as H2SO4 and K2S4O6 at the tested concentrations did not differentiate between service-exposed and solution annealed specimens for their corrosion susceptibility. Slow strain rate testing of Type 347 SS in both the service-exposed and solution annealed conditions showed susceptibility to stress corrosion cracking in environment containing NaCl + H2S, while the alloy did not show susceptibility to SCC in H2SO4 and K2S4O6. The long-term service exposure did not noticeably influence the SCC susceptibility of Type 347 SS under the tested conditions.

Guidelines for Production of API Pipelines Steels Suitable for Hydrogen Induced Cracking (HIC) Service Applications

2010 ◽  
Author(s):  
Douglas G. Stalheim ◽  
Bernhard Hoh
Keyword(s):  
Mechanical Property ◽  
Natural Gas ◽  
Pipeline Steel ◽  
Steel Production ◽  
The Other ◽  
Corrosion Mechanism ◽  
Pipeline Steels ◽  
Hydrogen Induced Cracking ◽  
Oil And Natural Gas ◽  
Sour Service

Worldwide oil and natural gas reserves can be classified as either sweet or sour service. The sour service classified oil and natural gas reserves contain some level of H2S making the product flowing through a steel pipeline corrosive. Due to this, the majority of the oil and natural gas reserves that have been drilled are of the sweet service nature. However as demand continues and supplies change, many of the remaining oil and natural gas reserves contain the H2S component and are of a sour service nature. These oil and natural gas reserves containing the H2S component through a corrosion mechanism will allow for diatomic hydrogen — in the presence of moisture — to disseminate to monatomic hydrogen and diffuse into the pipeline steel microstructure. Depending on the microstructure and level of cleanliness the monatomic hydrogen can become trapped at areas of high residual stress, recollect to diatomic hydrogen and creating partial pressures that exceed the tensile strength of the steel resulting in cracking. Therefore transmission pipelines are being built to transport sour service oil or natural gas requires steels with hydrogen induced cracking (HIC) resistance. Alloy designs, steel making processing, continuous casting, plate or strip rolling, pipe forming, and last not least corrosion testing are all key components in producing pipeline steels that are resistant to HIC applications and meeting the NACE TM0284 specifications. However, producing steels that have good HIC performance do not necessarily meet other mechanical property requirements such as strength and YT ratios. Balance has to be achieved to meet not only the HIC requirements but the other required mechanical properties. Mastering this complex HIC process poses a serious challenge to pipe producers and their primary material suppliers. The capability of producing HIC steel grades according to critical specifications and/or standards clearly distinguishes excellent steel producers from good steel makers. This paper will discuss the basics of the hydrogen induced cracking phenomenon, the requirements of the NACE TM0284 specification and give guidelines for steel production of API pipeline steels that not only can meet the specification requirements the NACE testing but also fulfill the other mechanical property requirements.

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